The catalytic dissociation of oxygen-bearing gaseous compounds employing a solid electrolyte having high oxygen-ion conductance is known as disclosed, for example, in article (A) above. The electrolyte comprises a stabilized oxygen-ion oxide such as scandia-stabilized zirconia. Porous electrodes are provided at opposite faces of the electrolyte, and a d-c potential is applied thereto for the formation of F-centers (trapped electrons) in the electrolyte at the cathode and V-centers (trapped holes) in the electrolyte at the anode. The oxygen-bearing gaseous compound to be dissociated is passed along the cathodic surface of the electrolyte while the opposite, anodic, surface is exposed to air. Dissociation of the gaseous oxygen-bearing compounds takes place at the cathodic surface of the electrolyte for the production of oxygen which, in ionic form, is pumped through the electrolyte by the applied electric field thereacross. The rate of decomposition at the surface of the electrolyte depends upon the concentration of F-centers thereat. Prior art methods depend upon increased current flow for increasing the production of F-centers and thereby to increase the rate of decomposition of the gaseous oxygen-bearing compound. The large power requirements are of particular disadvantage where the method is employed in vehicle exhaust systems for treating exhaust gases of internal combustion engines, and the like, for the removal of nitrogen oxides and carbon monoxide therefrom.
It now has been found that the above-described catalytic decomposition process may be effected with the expenditure of substantially no electrical power.